Thickening glyphosate formulations

ABSTRACT

The present invention generally relates to a glyphosate formulation with enhanced viscosity, said formulation containing a thickening composition comprising at least one nitrogen-containing surfactant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/059,449, filed Feb. 17, 2011, which is a national stage filing under35 U.S.C. §371 of PCT/EP2009/060588, filed Aug. 17, 2009, which claimspriority to U.S. Provisional Patent Application No. 61/090,010, filedAug. 19, 2008, and European Patent Application No. 08163910.6, filedSep. 9, 2008, the contents of which herein incorporated by reference tothe extent not inconsistent with the present disclosure.

FIELD OF THE INVENTION

The present invention relates to a glyphosate formulations thickened bynitrogen containing surfactants.

BACKGROUND OF THE INVENTION

Glyphosate is the most widely used herbicide in the world. It is a broadspectrum herbicide, meaning it controls both narrow leaf grass and broadleaf weed. Since it has very limited solubility in water, glyphosateacid is usually first converted to a soluble salt. Examples areisopropyl amine (IPA), monoethanol amine (MEA), diethanol amine (DEA),triethanol amine (TEA), sodium (Na), potassium (K), ammonium (NH4), andtrimesium.

IPA glyphosate (with some surfactants) was first commercialized asROUNDUP® Original by Monsanto because it was relatively easy toformulate. Glyphosate formulations with other salts, in particular theammonium and potassium, have been introduced to market recently.

Use of a concentrated aqueous formulation of glyphosate in the form of asalt made with the inorganic base ammonia and potassium is advantageous.Ammonia and potassium are low in costs, readily available, low inmolecular weights, and are relatively soluble in water. Additionally,they are natural nutrients for the growth of plants and other organisms.

The use of ammonium and potassium salts of glyphosate for preparingaqueous concentrate formulations of glyphosate suitable for killing andcontrolling plants has, however, been somewhat limited due todifficulties arising from chemical and physical properties of theammonium and potassium salts of glyphosate, and lack of biologicallysuitable surfactants for preparing high-loaded liquid concentrates ofsuch salts. If the biologically suitable surfactants are used, thesurfactants tend to lack the property of thickening the glyphosateformulation to desirable viscosity even at highest glyphosateconcentration allowable for a liquid formulation. The desired highviscosity in ROUNDUP® Original formulation arises mainly from the IPA asthe counterion for glyphosate and not from the surfactant used in theformulation. If K and NH4 glyphosate is formulated into the same 360g/l, the viscosity is much lower than ROUNDUP® Original. As a matter offact, even at much higher concentration, such as 540 g/l, the viscosityof the K glyphosate formulation (e.g., ROUNDUP® WeatherMax, 45 cps/22°C.) is still lower than the viscosity of the ROUNDUP® Original (54cps/22° C.). Glyphosate rates and concentrations given herein, evenwhere the glyphosate is present as a salt or salts, are expressed asacid equivalent (ae) unless the context demands otherwise.

Because of the much lower viscosity exhibited in lower than 360 g/l inthe case of IPA-glyphosate or in 360 g/l in the case of K- andNH4-glyphosate formulations, many farmers feel that they are being shortchanged by manufacturers in that they are receiving a watered downproduct.

Over the years, there has been a request from market place for aglyphosate thickener to improve formulation aesthetics. Accordingly,thick glyphosate formulations, especially the K and NH4 glyphosateformulations, are needed in the market place. However, thickening aglyphosate formulation to desired viscosity, typically 40 cps or higher,is technically challenging. For example, it has previously not beenpossible to thicken a K and NH₄ glyphosate formulation in theconcentration range of 360 to 540 g/l. Gelling a glyphosate formulationpresents even bigger challenges. When attempting to thicken suchformulations, those skilled in the art commonly use water-solublepolymeric thickeners. However, none of the commonly used polymerthickeners works in concentrated glyphosate formulations because theylose their thickening ability as they have a tendency to separate out ofsolution.

Viscosity requirements vary depending on the specific application. Forexample, a wiper application requires the formulation to have higherviscosity. Glyphosate formulations generally have higher viscosity asthe concentration of glyphosate increases. Farmers sometimes useundiluted Roundup® Original in the wick application to insure highenough viscosity to minimize dripping off. However, use of the undilutedRoundup® Original in the wick application is uneconomical as in thosecases it is desirable to use a less concentrated glyphosate. However,use of less concentrated glyphosate formulations presents a potentialdripping problem due to low viscosity. Therefore, there is need tothicker diluted glyphosate formulations for wick application to reducethe dripping.

During the spraying application of a dilute pesticide solution, somefine droplets have the potential to drift with wind to unintended areacausing damage to the crops in the area. Farmers typically use a watersoluble polymer such as guar gum as the drift control agent to controlthe drift. It is well known that even a small increase in viscosity(˜2-3 cps) caused by addition of the guar gum in the dilute pesticidesolution has significant effect on drift.

The present inventors have discovered that certain classes of nitrogencontaining surfactants can thicken glyphosate formulations veryeffectively.

SUMMARY OF THE INVENTION

The present invention generally relates to a thickened glyphosateformulation and to a method of thickening glyphosate. In accordance withthe invention, glyphosate formulations are thickened by use of at leastone nitrogen containing surfactant of general formula (A)-(F) asdescribed below. The glyphosate formulation thickened in accordance withthe present invention generally has an increased viscosity of 5 cps ormore in the case of a concentrate or 1 cps or more in the case of aready-to-spray solution after the addition of the at least one of thedescribed nitrogen containing derivatives of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to a thickened glyphosateformulation and to a method of thickening glyphosate. In accordance withthe invention, glyphosate formulations are thickened by use of athickening composition which comprises at least one nitrogen-containingsurfactant of general formula (A)-(F) as described below.

A first class of nitrogen-containing surfactants is represented bygeneral formula (A), below.

where R¹ is C16 to C22 linear or branched, saturated or unsaturatedhydrocarbon chain, n=1-4 and m=1-4. In another embodiment n=1-2, andm=1-2. Non-limiting examples of nitrogen containing surfactants ofgeneral formula (A) include, but are not limited to tallowamine-2EO,erucicamine-2EO and mixtures thereof.

A second class of nitrogen-containing surfactants is represented bygeneral formula (B), below.

where R¹ is C16 to C22 linear or branched, saturated or unsaturatedhydrocarbon chain; A is C1 to C6 linear or branched saturated orunsaturated hydrocarbon chain, and B is CH₃, O (oxygen), or CH₂—COO; X⁻is an anion including, but not limited to chloride, bromide ormethylsulfate; q is 0 when B is oxygen or CH₂—COO or 1 when B is CH₃; R²and R³ are independently CH₃ or CH₂CH₂OH. Non-limiting examples ofcompounds in accordance with formula (B) include tallowdimethylamidopropylamine oxide, erucic dimethylamidopropylamine methylchloride quaternary, erucic dimethylamido betaine and mixtures thereof.

A third class of nitrogen-containing surfactants is represented bygeneral formula (C), below.

where R⁴ is C20 to C22 linear or branched, saturated or unsaturatedhydrocarbon chain; n=1-4, m=1-4; in another embodiment n=1-2, and m=1-2,and X⁻ is an anion such as chloride, bromide or methylsulfate. Anon-limiting example of a nitrogen containing surfactant according togeneral structure (C) is erucicamine-2EO methylchloride quaternary(i.e., Ethoquad E/12), wherein R⁴ is C22 from erucic acid.

A fourth class of nitrogen-containing surfactants is represented bygeneral formula (D), below.

where R⁵ is C6 to C22 linear or branched, saturated or unsaturatedhydrocarbon chain; A is C1 to C6 linear or branched, saturated orunsaturated hydrocarbon chain, x=1-6, n=1-4, m=1-4, X⁻ is an anion suchas chloride, bromide or methylsulfate and q is 0 or 1. In anotherembodiment x=1-3, n=1-2, and m=1-2. Non-limiting examples of compoundsin accordance with formula (D) are C12/13 etheramine-2EO and thequaternary ammonium product thereof.

A fifth class of nitrogen-containing surfactants is represented bygeneral formula (E), below.

Where R⁶ is C12-C22 linear or branched, saturated or unsaturatedhydrocarbon chain, q=0 or 1, r=2-6, and p=0-5. R⁷, R⁸ and R⁹ are eachindependently chosen from H, CH₃, CH₂—CH₂—OH, CH₂—COOM or CH₂CH₂COOM (Mis comprised of H, Na, K, or NH4) with at least one group being CH₂—COOMor CH₂CH₂COOM. Non-limiting examples of nitrogen containing surfactantsin accordance with general formula (E) include, but are not limited tococo amphocarboxyglycinate (R⁶=coco, q=1, r=2, p=1, R⁷ is CH₂COO Na, R⁸is H or CH₂CH₂OH, and R⁹, different than R⁸, is CH₂CHOH or H),oleylampho polycarboxy glycinate (R⁶=oleic, q=0, r=3, p=3, and R⁷, R⁸and R⁹ are CH₂CH₂COO Na), and mixtures thereof.

A sixth class of nitrogen-containing surfactants is represented bygeneral formula (F), below.

Where R⁶ is C12-C22 linear or branched, saturated or unsaturatedhydrocarbon chain, q=0 or 1, r=2-6, and p=0-5. X⁻ is an anion such asacetate, nitrate, halide, methyl sulfate, or ethylsulfate. R¹⁰ is eitherCH₂CH₂OH or CH₃. Non-limiting examples of the compounds in accordancewith formula (F) include tris(2-hydroxyethyl) tallowalkyl ammoniumacetate and (2-hydroxyethyl) tallow dimethyl ammonium acetate.

Generally, the invention is suitable for a diluted and ready-to-sprayglyphosate solution or a concentrated glyphosate formulation. Thesuitable glyphosate concentration of the invention is from about 0.5 to45 wt % a.e., from about 0.5 to about 40 wt %. a.e., or from about 0.5%-30% a.e. The concentrated glyphosate formulation typically containsmore than about 10% glyphosate a.e. Typically, the formulations of thepresent invention have a pH greater than about 4, greater than about4.6, greater than about 4.7, greater than about 4.8, or greater thanabout 4.9.

The concentrated glyphosate formulation thickened in accordance with thepresent invention generally has an increased viscosity of 5 cps, inanother embodiment an increased viscosity of 10 cps, in anotherembodiment an increased viscosity of 15 cps, and in yet in anotherembodiment an increased viscosity of 20 cps, or more after the additionof the at least one of the described nitrogen containing derivatives ofthe invention. The ready-to-spray glyphosate formulation thickened inaccordance with the present invention generally has an increasedviscosity of 1 cps, in another embodiment an increased viscosity of 2cps, in another embodiment an increased viscosity of 3 cps, and in yetin another embodiment an increased viscosity of 5 cps, in anotherembodiment at least 10 cps, in another embodiment at least 15 cps, andin yet in another embodiment at least 20 cps or more after the additionof the at least one of the described nitrogen containing derivatives ofthe invention. More particularly, glyphosate formulations containing thethickening agent(s) of the invention in effective amounts typicallyexhibit increased viscosity compared to the same formulations notcontaining the thickening agents of the invention.

It is well known to the skilled in the art that to measure accuratelythe viscosity value for a sample with very low viscosity (˜1.0 cp) aU-tube viscometer based on mass flow under gravity shall be used.

For application to a field for control of weeds, a typical formulationaccording to the invention contains glyphosate acid equivalent in therange of from about 0.5 to 3 wt. %, typically 1 to 2 wt. %. However,stronger mixtures, e.g., in the range from about 2 to about 15 wt. %surfactant may be desirable for some applications. In some specialapplications, a>360 g/l glyphosate formulation is used directly withoutfurther dilution.

The nitrogen containing surfactants forming the thickening adjuvantcomposition of the invention are either commercially available or can bemanufactured by procedures known to those skilled in the art.

The thickening composition of the invention is added to said glyphosateformulation in an amount effective to thicken said formulation to thedesired degree. In most cases, said effective amount is exemplified by aweight ratio of glyphosate (a.e.) to thickening composition of fromabout 25:1 to about 0.5:1, typically from about 20:1 to about 1:1 and,in another embodiment, from about 8:1 to about 1.5:1. In most cases,said effective amount is exemplified by a concentration range in totalformulation between 0.05%-10%, preferably 0.2%-8%, or more preferably0.5%-5%.

Thickened herbicidal formulations of the present invention can, inaddition to the thickening composition/adjuvants set forth in the aboveformulae, contain additional components including but not limited to,additional surfactants or other additives. It is preferred that when theformulations of the invention do contain such additional components,that such additional components are substantially non-irritating to theeye, substantially non-toxic to aquatic life, and have acceptablebio-efficacy. Such additional components include surfactants such ascationic, anionic, nonionic, and amphoteric surfactants. Thesesurfactants are disclosed in McCutcheon's Emulsifier and Detergents,North America Edition, 2006. Non-limiting examples of preferred cationicsurfactants are alkoxylated alkylamine and its quaternary derivative,alkoxylated etheramine and its quaternary derivative, alkoxylated alkylamine oxide, alkoxylated alkyl etheramine oxide, alkyl amidopropyl amineoxide, alkyl trimethyl ammonium chloride, and alkyldimethylamidopropylamine. Non-limiting examples of preferred anionicsurfactants are alkylsulfate, alkylethersulfate, alkylsulfonate,alkylsulfosuccinate, alkoxylated phosphate ester, alkyl alpha olefinsulfonate, alkyl n-methyl taurate, fatty acid isethionate, and alkylether carboxylate. Non-limiting examples of preferred nonionicsurfactants are sorbitan ester and its alkoxylated derivative, sorbitolester and its alkoxylated derivative, fatty acid ester, castor oilalkoxylate, alcohol alkoxylate, alkanolamide, alkanolamide alkoxylate,and alkyl polyglycoside. Non-limiting examples of preferred amphotericsurfactants are alkyl betaine, alkyl amidopropyl betaine,alkylamphoacetate, alkylamphodiacetate, alkylamphocarboxylate,alkylamphopropionate, alkylamphodipropionate, alkyl amidoaminecarboxylate, alkylamphohydroxypropyl sulfonate, alkyl sultaine, alkylamidopropyl hydroxyl sultaine, alkyl dihydroxyethyl glycinate, and alkylaminopropionate.

The present invention encompasses not merely formulations of glyphosate,but also relates to other herbicidal compositions comprising at leastone co-herbicidal active, and at least one surfactant, wherein said atleast one surfactant comprises the adjuvants of the invention. Anherbicidal composition according to the invention can optionallycomprise other additives such as ammonium sulfate, potassium sulfate,potassium chloride, sodium sulfate, urea, glycerol, glycols,polyglycols, water soluble polymers, or mixtures thereof. A contemplatedcomposition can optionally include one or more of the following:quick-burn additive, humectant, co-herbicide, other pesticides, otheramine compounds, e.g., dimethylamine, isopropylamine, triethylamine,diethanolamine, dye, pigment, corrosion inhibitor, thickener, dispersingagent, calcium sequestrant, defoamer, antifreeze, pour-point depressant,anti-gelling agents, pH modifiers, preservatives, hydrotropes, solvents,process aids, or mixtures thereof.

Combinations of glyphosate salts and co-herbicide salts are specificallycontemplated by the present invention. Preferably, additives used inglyphosate compositions of the present invention possess sufficientsolubility or dispersibility in a concentrated aqueous potassium orammonium glyphosate solution at a pH of from about 4 to about 7 to allowdesired concentrations to be attained.

Where a co-herbicide is included in the formulation, it is preferredthat the co-herbicide be water-soluble and will not form precipitatewith the surfactants of the present invention and glyphosate, and morepreferred that it be included in the form of an amine salt, sodium,ammonium or potassium salt. Examples of suitable co-herbicides areAcetochlor, Acifluorfen, Aclonifen, Alachlor, Ametryn, Amidosulfuron,Aminopyralid, Amitrole, Anilofos, Asulam, Atrazine, Azafenidin,Azimsulfuron, Benazolin, Benfluralin, Bensulfuron-methyl, Bentazone,Bifenox, Binalafos, Bispyribac-sodium, Bromacil, Bromoxynil, Butachlor,Butroxidim, Cafenstrole, Carbetamide, Carfentrazone-ethyl, Chloridazon,Chlorimuron-ethyl, Chlorobromuron, Chlorotoluron, Chlorsulfuron,Cinidon-ethyl, Cinosulfuron, Clethodim, Clomazone, Clopyralid,Cloransulam-methyl, Clorsulfuron, Cyanazine, Cycloate, Cyclosulfamuron,Cycloxydim, Dalapon, Desmedipham, Dicamba, Dichlobenil, Dichlormid,Diclosulam, Diflufenican, Dimefuron, Dimepipeate, Dimethachlor,Dimethenamid, Diquat, Diuron, Esprocarb, Ethalfluralin,Ethametsulfuron-methyl, Ethofumesate, Ethoxysulfuron, Fentrazamide,Flazasulfuron, Florasulam, Fluchloralin, Flufenacet, Flumetsulam,Flumioxazin, Fluometuron, Flupyrsulfuron-methyl, Flurochloridone,Fluroxypyr, Flurtamone, Fomesafen, Foramsulfuron, Glufosinate,Hexazinone, Imazamethabenz-m, Imazamox, mazapic, Imazapyr, Imazaquin,Imazethapyr, Imazosulfuron, Iodosulfuron, Ioxynil, Isoproturon,Isoxaben, Isoxaflutole, Lactofen, Lenacil, Linuron, Mefenacet,Mesosulfuron-Methyl, Mesotrione, Metamitron, Metazachlor,Methabenzthiazuron, Metobromuron, Metolachlor, Metosulam, Metoxuron,Metribuzin, Metsulfuron-methyl, Molinate, MSMA, Napropamide,Nicosulfuron, Norflurazon, Oryzalin, Oxadiargyl, Oxadiazon, Oxasulfuron,Oxyfluorfen, Paraquat, Pendimethalin, Phenmedipham, Picloram,Pretilachlor, Profoxydim, Prometryn, Propanil, Propisochlor,Propoxycarbazone, Propyzamide, Prosulfocarb, Prosulfuron,Pyraflufen-ethyl, Pyrazosulfuron, Pyridate, Pyrithiobac, Quinclorac,Quinmerac, Rimsulfuron, Sethoxydim, Simazine, S-Metolachlor,Sulcotrione, Sulfentrazone, Sulfosulfuron, Tebuthiuron, Tepraloxydim,Terbuthylazine, Terbutryn, Thifensulfuron-methyl, Thiobencarb,Tralkoxydim, Tri-allate, Triasulfuron, Tribenuron-methyl, Triclopyr,Trifloxysulfuron, Trifluralin, Triflusulfuron-methyl, Tritosulfuron, andmixtures and combinations thereof. More preferred co-herbicides areAcetochlor, Aminopyralid, Amitrole, Atrazine, Bensulfuron-methyl,Bromoxynil, Chlorimuron-ethyl, Clethodim, Clomazone, Dicamba,Dimethenamid, Flumetsulam, Glyfosinate, Imazethapyr, Imazamox,Isoproturon, Isoxaflutole, Mesotrione, Metamitron, Metosulam,Metsulfuron-methyl, Nicosulfuron, Paraquat, Pendimethalin, Picloram,Propanil, Rimsulfuron, S-Metolachlor, Tribenuron-methyl, Triclopyr,Trifluralin, and mixtures and combinations thereof. The most preferredco-herbicides are 2,4-D, Atrazine, Aminopyralid, Amitrole,Bensulfuron-methyl, Dicamba, Flumetsulam, Glyfosinate, Imazamox,Isoproturon, Metosulam, Metsulfuron-methyl, Nicosulfuron, Pendimethalin,Rimsulfuron, Tribenuron-methyl, and mixtures and combinations thereof.In various advantageous embodiments, the formulation comprises aco-herbicide selected from the group consisting of diuron, fluometuron,prometryn, and combinations thereof.

Further in accordance with the present invention, the formulation maycomprise a co-herbicide selected from the group consisting of4-chlorophenoxyacetic acid (4-CPA) or a salt thereof,2,4-dichlorophenoxyacetic acid (2,4-D) or a salt thereof,3,4-dichlorophenoxyacetic acid (3,4-DA) or a salt thereof,4-chloro-2-methylphenoxyacetic acid (MCPA) or a salt thereof,2,4,5-trichlorophenoxyacetic acid (2,4,5-T) or a salt thereof,2-(3-chlorophenoxy)propanoic acid (cloprop) or a salt thereof,2-(4-chlorophenoxy)propanoic acid (4-CPP) or a salt thereof,2-(2,4-dichlorophenoxy)propanoic acid (dichlorprop) or a salt thereof,2-(3,4-dichlorophenoxy)propanoic acid (3,4-DP) or a salt thereof,2-(2,4,5-trichlorophenoxy)propanoic acid (fenoprop) or a salt thereof,2-(4-chloro-2-methylphenoxy)propanoic acid (mecoprop) or a salt thereof,4-(4-chlorophenoxy)butanoic acid (4-CPB) or a salt thereof,4-(2,4-dichlorophenoxy)butanoic acid (2,4-DB) or a salt thereof,4-(3,4-dichlorophenoxy)butanoic acid (3,4-DB) or a salt thereof,4-(4-chloro-2-methylphenoxy)butanoic acid (MCPB) or a salt thereof,4-(2,4,5-trichlorophenoxy)butanoic acid (2,4,5-TB) or a salt thereof,3-amino-2,5-dichlorobenzoic acid (chloramben) or a salt thereof,3,6-dichloro-2-methoxybenzoic acid (dicamba) or a salt thereof,2,3,6-trichlorobenzoic acid (2,3,6-TBA) or a salt thereof,2,3,5-trichloro-6-methoxybenzoic acid (tricamba) or a salt thereof,4-amino-3,6-dichloro-2-pyridinecarboxylic acid (aminopyralid) or a saltthereof, 3,6-dichloro-2-pyridinecarboxylic acid (clopyralid) or a saltthereof, 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid (picloram) ora salt thereof, 3,5,6-trichloro-2-pyridinyl)oxyacetic acid (triclopyr)or a salt thereof, and combinations thereof.

Regardless of the particular co-herbicide, or combination ofco-herbicides present in the formulation, the weight ratio of glyphosate(a.e.) to one or more co-herbicides is typically from about 0.5 to about4.0 and, still more typically, from about 1.0 to about 2.0.

Formulations of the present invention may be generally prepared bymixing the glyphosate salt solution, prepared as outlined above,together with other ingredients in a suitable mixing vessel withagitation, such as a blender.

This invention also relates to an herbicidal method of using acontemplated composition in an amount effective to kill or controlunwanted vegetation by either diluting an aqueous concentratecomposition in water to provide a diluted mixture for application orapplying directly the concentrate without further dilution to foliage ofthe vegetation to be killed or controlled. The glyphosate formulation ofthe invention should be applied to plant foliage at an application ratesufficient to give the desired effect. Application rates are usuallyexpressed as amount of glyphosate ae per unit area of land treated, e.g.grams ae per hectare (g ae/ha). What constitutes a “desired effect”varies according to the standards and practice of those who investigate,develop, market, and use glyphosate products. For example, the amount ofglyphosate ae applied per unit area to give, consistently and reliably,at least 85% control of a plant species as measured by growth reductionor mortality is often used to define a commercially effective rate.

Preferred compositions of the invention provide equivalent herbicidalefficacy by comparison with commercial standard formulations ofglyphosate “Herbicidal efficacy,” as used herein, refers to anyobservable measure of control of plant growth, which can include one ormore of the actions of (1) killing, (2) inhibiting growth, reproductionor proliferation, and (3) removing, destroying, or otherwise diminishingthe occurrence and activity of plants.

The selection of application rates that are biologically effective for aspecific glyphosate formulation, such as a formulation of the presentinvention, is within the skill of the ordinary agricultural scientist.Those skilled in the art will likewise recognize that individual plantconditions, weather, and growing conditions, as well as the specificformulation selected, will influence the degree of biologicaleffectiveness achieved in practicing this invention. Useful applicationrates can therefore depend upon all of the above conditions. Muchinformation is known about appropriate application rates for glyphosateformulations in general. Over two decades of glyphosate use andpublished studies relating to such use have provided abundantinformation from which a weed control practitioner can select glyphosateapplication rates that are herbicidally effective on particular speciesat particular growth stages in particular environmental conditions.

Various application methods may be employed including broadcastspraying, directed spraying or wiping the foliage with a dilutedcomposition or a concentrate of this invention. Depending on the degreeof control desired, the age and species of the plants, weatherconditions and other factors, typically the glyphosate application rateis an herbicidally effective amount of about 0.1 to about 10 kg ae/haand preferably from about 0.25 to about 2.5 kg ae/ha, although greateror lesser amounts may be applied.

The invention will now be illustrated by the following non-limitingexamples.

EXAMPLES

Anionic and nonionic surfactants and commonly used polymer thickenersdid not showed significant thickening property in concentratedglyphosate formulations.

It was unexpectedly discovered that certain nitrogen containingsurfactants thickened glyphosate formulations very effectively.Non-limiting examples are Ethomeen T/12, Ethomeen S/12, C12/13etheramine-2EO, Aromox APA-T, Arquad APA-E E, Ethoquad E/12 (i.e.,erucicamine-2EO methylchloride quaternary), Erucic DMAPA betaine,Ampholak XO7/C, Ampholak XCO-30, tris(2-hydroxyethyl) tallowalkylammonium acetate, and (2-hydroxyethyl) tallow dimethyl ammonium acetate.

Example 1

Viscosity of 23.2 wt % a.i. K-glyphosate+Thickener+water

#1 #2 #3 #4 #5 #6 #7 #8 K-glyphosate 23.3  23.2  23.2 23.2 23.2 23.223.2 23.3 Arquad APA-E E 0.14 0.52 (Erucic DMAPA Quat) Aromox APA-T 3.0(Tallow DMAPA oxide) Ethomeen SV/12 10 (Soyamine-2EO) Ethomeen C/12 10(Cocamine-2EO) Ethomeen SV/15 10 (Soyamine-5EO) Erucic DMAPA Betaine 0.5Ethoquad E/12 0.5 Naxonate 4LS 1.09 1.05 (40% SXS) Water 75.47  75.13 73.7 66.7 66.7 66.7 76.3 76.3 Viscosity, cps* 58**   122**   417 44 <6<6 Thick Thick (20 rpm/22° C.) hazy clear *Brookfield viscometer.**Behaved like egg-white.

It can be seen in this example that soyamine-2EO at 10%, erucic-2EO quatat 0.5%, Erucic DMAPA quat at 0.14%, Erucic DMAPA betaine at 0.5% andtallow DMAPA oxide at 3% thickened the K-glyphosate solution todesirable viscosity. On the other hand, Cocoamine-2EO and soyamine-5EO,though structurally similar to the soyamine-2EO, did not show thickeningability at 10% surfactant concentration.

All formulations in this example were stable between 0° C. and 40° C.

Example 2

Viscosity of 37.34 wt % a.i. K-glyphosate+thickener+water (to 100%). (20rpm)

Description of Wt % of Viscosity (cps) Thickener Thickener Thickener @22° C. @ 2° C. Ethomeen SV/12 Soyamine-2EO 1.00 15 2.00 42 32 3.00 2594.00 1581 5.20 viscous Ampholak XCO-30 Na Cocoampho carboxy 2.00 55 28glycinate 30% 5.20 553 10.00 1791 Aromox APA-T Tallow DMAPA oxide 3.00Clear gel Ethoduomeen C/13 Coco diamine-3EO 5.20 thin Ethomeen T/15Tallowamine-5EO 5.20 9 Ethoquad T/12 Tallowamine-2EO MeCl 5.20 thinEthoquad T/15 Tallowamine-5EO MeCl 5.20 thin Ethotetrameen T/15 Tallowtetramine-5EO 5.20 thin Ethomeen C/12 Cocoamine-2EO 5.20 9 Ethomeen T/20Tallowamine-10EO 5.20 9 Ampholak 7CX/C Cocoampho polycarboxy 15.00 thinglycinate 40% Ampholak XO7/C Oleylampho polycarboxy 15.00 7 glycinate40% Ampholak YJH-40 Octyl iminodipropionate 40% 15.00 thin Amphoteen 24Lauryldimethyl betaine 30% 15.00 21 Water Water 5.20 6

It can be seen in this example that, at relatively low concentration of2%, soyamine-2EO and sodium cocoamphocarboxy glycinate thickenedK-glyphosate solution dramatically to a desirable viscosity. An amineoxide, exemplified by tallow DMAPA oxide, gelled K-glyphosateformulation at only 3%.

On the other hand, cocoamine-2EO, tallowamine-5EO and 10EO,tallowamine-2EO and 5EO quats, polyamine ethoxylates (cocodiamine-3EOand tallow tetramine-5EO), though structurally similar to thesoyamine-2EO, did not show thickening ability in this system. With 1%soyamine-2EO, the viscosity of K-glyphosate formulation was 15 cps whichwas already higher than the viscosity of 9 cps achieved with 5.2%cocoamine-2EO or tallowamine-5EO.

Cocoampho polycarboxy glycinate, oleylampho polycarboxy glycinate, octyliminodipropionate, and Lauryldimethyl betaine, though showed verysimilar physical properties to the sodium cocoamphocarboxy glycinate inmany applications, did not show thickening ability in this system. With2% sodium cocoamphocarboxy glycinate (30%), the viscosity of theK-glyphosate formulation was 55 cps which was already much higher thanthe viscosity (7 cps or less) achieved with 15% cocoampho polycarboxyglycinate (40%), oleylampho polycarboxy glycinate (40%), or octyliminodipropionate (40%), or lauryldimethyl betaine (30%).

All formulations in this example were stable between 0° C. and 40° C.

Example 3

Viscosity of 48.9% K-glyphosate+10% Thickeners+water (to 100%)

#1 #2 #3 #4 #5 #6 K-glyphosate, 58 48.9 48.9 48.9 48.9 48.9 wt % a.i.Water, wt % 42 51.1 41.1 41.1 41.1 41.1 Ethomeen T/16 10 (Tallowamine-6EO), wt % Ethomeen C/12 10 (Cocamine-2 EO), wt % Ethomeen T/12 10(Tallowamine-2 EO), wt % Ethomeen EA- 10 1213/12 (C1213 etheramine-2EO), wt % Viscosity, cps 60 16 Gel Gel 65 Separated (20 rpm/22° C.)

All formulations in this example were stable between 0° C. and 40° C.except for #6. The data show that at 58% and 48.9% solids, theglyphosate formulation had a viscosity of 60 cps and 16 cps,respectively (#1 and #2).

When about 9% K-glyphosate solid and 1% water in formulation #1 werereplaced by 10% tallowamine-2EO or C12/13 etheramine-2EO, theformulations (#3 and #4) became clear gels.

However, when about 9% K-glyphosate solid and 1% water in formulation #1were replaced by 10% cocoamine-2, which is structurally similar totallowamine-2EO and C1213 etheramine-2EO, the formulation viscosity (#5)remained relatively unchanged.

Moreover, when about 9% K-glyphosate solid and 1% water in formulation#1 were replaced by 10% tallowamine-6EO, which is structurally similarto tallowamine-2EO, the formulation (#6) became unstable and separatedat room temperature.

This example suggested that in order for a surfactant to be able tothicken a glyphosate formulation, the surfactant should be compatible inthe glyphosate system, as a necessary condition. However, not allcompatible surfactants possess the ability to thicken glyphosate.

Example 4

Viscosity of IPA, K and NH4-glyphosate+Amphoteric Surfactants+water (to100%)

Wt % Ampholak Ampholak Ampholak Ampholak Room a.i. Glyphosate 7CX/CXO7/C YJH-40 XCO-30 Temp 55.8 IPA-glyp 10 clr 49.6 IPA-glyp 20 clr 43.4IPA-glyp 30 clr 55.8 IPA-glyp 10 clr 49.6 IPA-glyp 20 clr 43.4 IPA-glyp30 clr 55.8 IPA-glyp 10 clr 49.6 IPA-glyp 20 clr 43.4 IPA-glyp 30 clr55.8 IPA-glyp 10 Clr, viscous 49.6 IPA-glyp 20 Clr, viscous 43.4IPA-glyp 30 Clr, viscous 52.2 K-glyp 10 clr 46.4 K-glyp 20 clr 40.6K-glyp 30 clr 52.2 K-glyp 10 clr 46.4 K-glyp 20 clr 40.6 K-glyp 30slight hazy 52.2 K-glyp 10 very hazy 46.4 K-glyp 20 hazy/sep 40.6 K-glyp30 hazy/sep 52.2 K-glyp 10 very hazy 46.4 K-glyp 20 hazy/sep 40.6 K-glyp30 clear gel 45 NH4-glyp 10 clr 40 NH4-glyp 20 clr 35 NH4-glyp 30 clr 45NH4-glyp 10 clr gel 40 NH4-glyp 20 clr 35 NH4-glyp 30 clr 45 NH4-glyp 10clr 40 NH4-glyp 20 clr 35 NH4-glyp 30 clr 45 NH4-glyp 10 very hazy 40NH4-glyp 20 hazy/sep 35 NH4-glyp 30 hazy gel

The data show that Ampholak XCO-30 and XO7/C had the ability to thickenglyphosate formulations. However, their thickening ability was verysensitive to the counter ions of glyphosate. Ampholak XO7/C, whichshowed the ability to gel NH4-glyphosate, did not show the ability togel K-glyphosate. On the other hand, Ampholak XCO-30 showed that the gelcould only be obtained with certain concentration range.

Moreover, Ampholak 7CX/C and YJH-40, structurally similar to AmpholakXCO-30 and XO7/C, didn't showed significant thickening ability inglyphosate formulations.

Example 5

#1 #2 #3 #4 K-glyphosate 18 16.45 36 2.47 Water 77.16 80.98 54 93.26Tris(2-hydroxy- 4.5 2.39 9 ethyl) tallowalkyl ammonium acetate (27%)(2-hydroxyethyl) 3.32 tallow dimethyl ammonium acetate (80.3%) Sodiumsalicylate 0.34 0.18 Sodium xylene 1 0.95 sulfonate (40%) Appearance atClear Clear Clear Clear room temperature gel viscous gel viscous

The data show that tris(2-hydroxyethyl) tallowalkyl ammonium acetate and(2-hydroxyethyl) tallow dimethyl ammonium acetate had the ability tothicken glyphosate formulations at high and low glyphosateconcentrations.

The data in the above examples (1-5) demonstrate that nitrogencontaining surfactants have the ability to thicken glyphosateformulations. However, it seems there was no logic behind the thickeningability of the surfactants in glyphosate system. It is difficult topredict the thickening property even within a family of surfactants. Forexample, tallowamine-2EO (and soyamine-2EO), erucid-2EO quat and C12/13etheramine-2EO are much better thickeners compared to structurallysimilar cocoamine-2EO, talloamine-5EO, tallowamine-2EO quat, and tallowpolyamine ethoxylates. Regarding the amphoteric surfactants studied,Ampholak XCO-30 (sodium cocoampho carboxy glycinate) and Ampholak XO7/C(oleylampho polycarboxy glycinate or sodium carboxymethyl oleylpolypropylamine) were found to be effective thickeners whilelauryldimethylbetaine, Ampholak 7CX/C (cocoampho polycarboxy glycinate)and Ampholak YJH-40 (octyl iminodipropionate) were not.

What is claimed is:
 1. A thickened glyphosate formulation whichcomprises at least one water soluble salt of glyphosate and a thickeningcomposition, wherein said thickening composition comprises at least onenitrogen containing surfactant of formula (E)

where R⁶ is C12-C22 linear or branched, saturated or unsaturatedhydrocarbon chain, r=2-6, and R⁷, R⁸ and R⁹ are each independentlychosen from H, CH₃, CH₂—CH₂—OH, CH₂—COOM or CH₂CH₂COOM, where M iscomprised of H, Na, K, or NH4, with at least one group being CH₂—COOM orCH₂CH₂COOM.
 2. The thickened glyphosate formulation of claim 1characterized in that said formulation has a glyphosate concentration ofgreater than 10% and an increased viscosity of at least 5 cps in aconcentrate with >10% glyphosate or at least 1 cps in a ready-to-spraysolution after the addition of the thickening agent.
 3. The thickenedglyphosate formulation of claim 1, wherein the thickening agent is usedin combination with a sulfonate derivative, an alkyl alpha olefinsulfonate, an alkyl alpha olefin salicylate, or mixtures thereof.
 4. Thethickened glyphosate formulation of claim 3 wherein said sulfonatederivative is sodium xylene sulfonate.
 5. The thickened glyphosateformulation of claim 1 wherein the glyphosate concentration is from 0.5to 45% wtae, preferably from 0.5 to 40 wt % ae, and more preferably from0.5 to 30 wt % ae.
 6. The thickened glyphosate formulation of claim 1wherein the concentration of said thickening agent is from 0.05 to 10%by weight based on the weight of the formulation, preferably from 0.2%to 8% by weight based on the weight of the formulation, more preferablyfrom 0.5 to 5% by weight based on the weight of the formulation.
 7. Thethickened glyphosate formulation of in claim 1 wherein said thickeningcomposition comprises sodium cocoampho carboxy glycinate, oleylamphopolycarboxy glycinateor combinations and/or mixtures thereof.
 8. Amethod of thickening a glyphosate formulation which comprises adding tosaid formulation a thickening effective amount of at least one nitrogencontaining surfactant of formula (E)

where R⁶ is C12-C22 linear or branched, saturated or unsaturatedhydrocarbon chain, r=2-6, and R⁷, R⁸ and R⁹ are each independentlychosen from H, CH₃, CH₂—CH₂—OH, CH₂—COOM or CH₂CH₂COOM, where M iscomprised of H, Na, K, or NH4, with at least one group being CH₂—COOM orCH₂CH₂COOM.
 9. The method of claim 8, wherein the thickening compositionis used in combination with a sulfonate derivative, an alkyl alphaolefin sulfonate, an alkyl alpha olefin salicylate, or mixtures thereof.10. The method of claim 8 wherein the concentration of said thickeningcomposition is from 0.05 to 10% by weight based on the weight of theformulation.